English Noun aerenchym (uncountable) Dated form of aerenchyma. 1905, Frederic Edward Clements, Research Methods in Ecology, page 134:The position and amount of aerenchym and the relative extent of sponge cells and air-spaces […] Anagrams Archenemy, arch enemy, arch-enemy, archenemyWikiwand - on Seamless Wikipedia browsing. On steroids.